Typically this might also depend on server you're running.
The interoperability tool is pretty accurate and you can always confirm with:
Looks like from CNA only M73KR -E and -Q are supported ( plus VM-FEX and VICs).
With UCSM at 2.2 based release, you can still have your server & adapter firmware at 2.1.3 with B200M2 and M81KR running ESXi5.5 and ESXi5.5U1.
This has been already tested and shown in the interop matrix
This is a supported combination
I am running b200m2 wih the m81kr card
I am stuck with this hardware but I need to upgrade to esxi 5.5
It looks like its not suppported but just wanted to see if anyone is running this configuration.
esxi 5.5 on b200m2 with M81KR
I'm running vmware 5.5 with firmware 2.2(1c) and a M81KR NIC. Booting is with local storage, so I can't confirm if this will work with features like boot from SAN.